Move compression functions to Utils::Gzip.

src/core/utils/gzip.cpp

@@ -0,0 +1,142 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2015  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include <QByteArray>
+#include <zlib.h>
+
+#include "gzip.h"
+
+bool Utils::Gzip::compress(QByteArray src, QByteArray &dest)
+{
+    static const int BUFSIZE = 128 * 1024;
+    char tmpBuf[BUFSIZE];
+    int ret;
+
+    dest.clear();
+
+    z_stream strm;
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.next_in = reinterpret_cast<uchar *>(src.data());
+    strm.avail_in = src.length();
+    strm.next_out = reinterpret_cast<uchar *>(tmpBuf);
+    strm.avail_out = BUFSIZE;
+
+    // windowBits = 15 + 16 to enable gzip
+    // From the zlib manual: windowBits can also be greater than 15 for optional gzip encoding. Add 16 to windowBits
+    // to write a simple gzip header and trailer around the compressed data instead of a zlib wrapper.
+    ret = deflateInit2(&strm, Z_BEST_COMPRESSION, Z_DEFLATED, 15 + 16, 8, Z_DEFAULT_STRATEGY);
+
+    if (ret != Z_OK)
+        return false;
+
+    while (strm.avail_in != 0) {
+        ret = deflate(&strm, Z_NO_FLUSH);
+        if (ret != Z_OK)
+            return false;
+
+        if (strm.avail_out == 0) {
+            dest.append(tmpBuf, BUFSIZE);
+            strm.next_out = reinterpret_cast<uchar *>(tmpBuf);
+            strm.avail_out = BUFSIZE;
+        }
+    }
+
+    int deflateRes = Z_OK;
+    while (deflateRes == Z_OK) {
+        if (strm.avail_out == 0) {
+            dest.append(tmpBuf, BUFSIZE);
+            strm.next_out = reinterpret_cast<uchar *>(tmpBuf);
+            strm.avail_out = BUFSIZE;
+        }
+
+        deflateRes = deflate(&strm, Z_FINISH);
+    }
+
+    if (deflateRes != Z_STREAM_END)
+        return false;
+
+    dest.append(tmpBuf, BUFSIZE - strm.avail_out);
+    deflateEnd(&strm);
+
+    return true;
+}
+
+bool Utils::Gzip::uncompress(QByteArray src, QByteArray &dest)
+{
+    dest.clear();
+
+    if (src.size() <= 4) {
+        qWarning("uncompress: Input data is truncated");
+        return false;
+    }
+
+    z_stream strm;
+    static const int CHUNK_SIZE = 1024;
+    char out[CHUNK_SIZE];
+
+    /* allocate inflate state */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = static_cast<uint>(src.size());
+    strm.next_in = reinterpret_cast<uchar *>(src.data());
+
+    const int windowBits = 15;
+    const int ENABLE_ZLIB_GZIP = 32;
+
+    int ret = inflateInit2(&strm, windowBits | ENABLE_ZLIB_GZIP); // gzip decoding
+    if (ret != Z_OK)
+        return false;
+
+    // run inflate()
+    do {
+        strm.avail_out = CHUNK_SIZE;
+        strm.next_out = reinterpret_cast<uchar *>(out);
+
+        ret = inflate(&strm, Z_NO_FLUSH);
+        Q_ASSERT(ret != Z_STREAM_ERROR); // state not clobbered
+
+        switch (ret) {
+        case Z_NEED_DICT:
+        case Z_DATA_ERROR:
+        case Z_MEM_ERROR:
+            inflateEnd(&strm);
+            return false;
+        }
+
+        dest.append(out, CHUNK_SIZE - strm.avail_out);
+    }
+    while (!strm.avail_out);
+
+    // clean up and return
+    inflateEnd(&strm);
+    return true;
+}